Set MaxResults if it is not set

[nckturner]

• EC2 pagination doesn't work if MaxResults is not set
• Only set if InstanceIds isn't set.

What type of PR is this?

Uncomment only one, leave it on its own line:

/kind bug

What this PR does / why we need it:
The describeInstances API doesn't paginate unless maxResults is set.
Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:
/hold

Does this PR introduce a user-facing change?:

Ensure pagination of EC2 describeInstances calls

[wongma7]

kubernetes/kubernetes#102927 this updated the cache to have a ttl of just 10 minutes. Seems like a very bad idea if we are trying to optimize our calls.

[nckturner]

/unhold

[wongma7]

do you mind double checking that describeAllInstancesUncached

cloud-provider-aws/pkg/providers/v1/instances.go

Line 153 in 58bc609

func (c *instanceCache) describeAllInstancesUncached() (*allInstancesSnapshot, error) {

ultimately calls this function? I am confident in my ctrl+clicking skills but just want to make 100% sure that we're covering all calls given that there are quite a few layers (describeAllInstancesUncached, describeInstances lowercase, DescribeInstances uppercase, sdk go's DescribeInstances uppercase...

[wongma7]

describeAllInstancesUncached calls c.cloud.describeInstances (c is for cache)

cloud-provider-aws/pkg/providers/v1/instances.go

Line 159 in 58bc609

instances, err := c.cloud.describeInstances(filters)

cloud-provider-aws/pkg/providers/v1/aws.go

Line 5002 in 58bc609

func (c *Cloud) describeInstances(filters []*ec2.Filter) ([]*ec2.Instance, error) {

c.cloud.describeInstances calls c.ec2.DescribeInstances (now c is for cloud)

cloud-provider-aws/pkg/providers/v1/aws.go

Line 5007 in 58bc609

response, err := c.ec2.DescribeInstances(request)

cloud.ec2 is a v1.EC2 interface

cloud-provider-aws/pkg/providers/v1/aws.go

Line 334 in 58bc609

type EC2 interface {

and the "real"/non-mock implementation of it by awsSdkEC2 is

cloud-provider-aws/pkg/providers/v1/aws.go

Line 964 in 58bc609

func (s *awsSdkEC2) DescribeInstances(request *ec2.DescribeInstancesInput) ([]*ec2.Instance, error) {

which calls s.ec2.DescribeInstances (now ec2 is an aws-sdk-go ec2.EC2 not a v1.EC2/awsSdkEC2)

cloud-provider-aws/pkg/providers/v1/aws.go

Line 731 in 58bc609

ec2 *ec2.EC2

[wongma7]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nckturner, wongma7

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [nckturner,wongma7]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment